Evidence check: VDR in the context of Sport

The vitamin D receptor (VDR) is often discussed in sports contexts because it influences muscle strength, bone metabolism, and immune function. Polymorphisms such as FokI (rs2228570) and BsmI (rs1544410) have been associated with differences in muscle mass, strength gains after training, and injury risk. However, the evidence is mixed: many studies are small, fail to replicate, or show only weak effects. Moreover, the impact is strongly modulated by actual vitamin D status – a genetic disadvantage can often be compensated by adequate levels. Therefore, a VDR gene test alone does not allow specific training or nutrition recommendations. It is more useful to measure serum 25(OH)-vitamin D levels. Supplementation should only be done if deficiency is confirmed, as overdosing is harmful. In the context of MyBody-X, note that their DNA tests for athletes often include markers with small effect sizes; clinical relevance is limited. In summary, VDR variants have a detectable but small influence on athletic performance parameters. The evidence does not support personalized training plans based solely on this gene.